Textured fabric printing system and method

Abstract

A print apparatus and print method is provided for patterned fabrics, particularly those with surface variations due to threadings. These threadings may be e.g. stitches and/or bindings arranged in the fabric that create the surface variations which create the pattern. The apparatus/method involves a vision system which detects the threadings at a granular level (e.g. detects individual stitches) and then determines how those stitches have moved due to fabric stretching. The computer and its software adjust the print design (often a color design) to match the distortion/warping of the fabric. In some cases, the printer can print along a line of the stitches at a width not much wider than the stitches at high precision and with precise alignment. The fabric printed may have reference markers to aid in identification of the threadings and a calibration process may be used for the printer to align the print and vision systems.

What is claimed is: 
     
         1 . A method of printing a patterned fabric comprising:
 imaging a section of patterned fabric with at least one imaging device to generate actual thread data indicative of a plurality of threadings which are a plurality of stiches in the fabric which stitches create low points in the fabric to create surface variations and/or are woven bindings which create the surface variations wherein the surface variations cause the fabric to have a three-dimensional pattern;   comparing the actual thread data to design thread data indicative of expected locations of each of the plurality of stitches and/or woven bindings, the comparing determining a print adjustment which accounts for distortion of the actual thread data relative to the design thread data;   adjusting print data indicative of a printed design to be printed on the pattern relative to design thread data for the section of the fabric, the adjusting utilizing the print adjustment to determine actual print data which adjusts the printed design to match the actual thread data;   printing the fabric using the actual print data;   moving the fabric to a next section of the fabric and repeating the imaging, comparing, adjusting and printing steps for the next section and each subsequent next section until the fabric is printed.   
     
     
         2 . The method of  claim 1  wherein the adjusting step for one of the next sections compares to a prior section of fabric such that the actual print data of the next section aligns with the prior section which is adjacent that next section. 
     
     
         3 . The method of  claim 1  wherein the imaging step further comprises imaging an area of the fabric which is expected to include location markings, the location markings indicative of a position on the fabric relative to the three dimensional pattern. 
     
     
         4 . The method of  claim 3  wherein when an expected location marking is detected, the comparing step's comparison of actual stitch data and design stitch data further uses the marking to calibrate to a location within the design stitch data which is imaged. 
     
     
         5 . The method of  claim 4  wherein the location markings are a plurality of stitches. 
     
     
         6 . The method of  claim 4  wherein the location markings are a plurality of stitches in a selvedge of the fabric. 
     
     
         7 . The method of  claim 1  wherein the at least one imaging device is at an imaging location and a movement device moves the section from the imaging location to a print location associated with a print unit for printing. 
     
     
         8 . The method of  claim 7  wherein more than one section of fabric is imaged prior to the section of fabric being printed. 
     
     
         9 . The method of  claim 7  wherein the movement device comprises a belt and an encoder measures movement of the fabric between the imaging location and the print location. 
     
     
         10 . The method of  claim 1  wherein the threadings are stitches and when printing the fabric with the actual print data one or more of the stitches are printed in a first color that is different from a second color printed on an area adjacent the stitches, with the area adjacent the stitches having a higher loft than at the stitches. 
     
     
         11 . A printing apparatus comprising:
 a feed unit configured to move a patterned fabric in a feed direction;   an imaging unit configured to image the fabric to detect a plurality of threadings in the fabric to generate actual threading data, the threadings create surface variations in the fabric which cause the fabric to include a three-dimensional pattern;   a processor configured to compare the actual threading data to design threading data indicative of expected locations of each of the plurality of threadings, the comparing determining a print adjustment which accounts for distortion of the actual threading data relative to the design threading data, the processor further configured to adjust print data indicative of a printed design to be printed on the three dimensional pattern relative to the design threading data, the adjusting utilizing the print adjustment to determine actual print data which adjusts the printed design to match the actual threading data;   a print unit arranged downstream of the imaging unit along the feed direction and the print unit configured to print the fabric using the actual print data.   
     
     
         12 . The apparatus of  claim 11  wherein the imaging unit is further configured to image a plurality of markers in the fabric, wherein the processor references at least one of the plurality of markers relative to the design stitch data to determine a location in the design stich data which is being imaged. 
     
     
         13 . The apparatus of  claim 11  wherein the feed unit moves a next section of the fabric to the print unit for printing and wherein the actual print data of the next section is adjusted to align with the actual print data of a previous section of the fabric. 
     
     
         14 . The apparatus of  claim 11  further comprising an encoder which measures movement of the fabric by the feed unit and provides a signal to the processor. 
     
     
         15 . The apparatus of  claim 14  wherein the fabric is imaged while the feed unit is moving the fabric past the imaging unit and the signal from the encoder is used to determine a lengthwise position for the actual threading data which is thereby used to align the fabric with the print unit. 
     
     
         16 . The apparatus of  claim 11  wherein the feed unit comprises an endless belt with a tacky or high friction surface which inhibits sliding and/or stretching of the fabric between the imaging unit and the print unit. 
     
     
         17 . The apparatus of  claim 11  wherein the plurality of threadings are a plurality of stitches in the fabric. 
     
     
         18 . The apparatus of  claim 11  wherein the plurality of threading are a plurality of woven bindings in the fabric. 
     
     
         19 . A fabric printer which utilizes a dynamic print buffer comprising:
 an imaging unit configured to image the fabric to detect a plurality of threadings in a plurality of sections of the fabric to generate actual threading data, the threadings create surface variations which thereby cause the fabric to be patterned;   a processor configured to compare the actual threading data to design threading data for each section of the fabric, the design stitch data indicative of expected locations of each of the plurality of threadings, the comparing determining a print adjustment which accounts for distortion of the actual threading data relative to the design threading data, the processor further configured to adjust print data indicative of a printed design to be printed on the pattern of the fabric relative to design threading data wherein the print data represents the printed design for a plurality of sections of the fabric, the adjusting utilizing the print adjustment to determine actual print data for each section of fabric which adjusts the printed design to match the actual threading data for each section of fabric;   a print unit arranged downstream of the imaging unit along a feed direction and the print unit including a print buffer which is configured to sequentially receive the actual print data for each section of the fabric and use that actual print data for each section of fabric to instruct a print head to print the fabric;   a feed unit which is configured to move the fabric such that each section of fabric is imaged with the imaging unit to generate the actual print data for each section of fabric and the feed unit then sequentially aligns each section of fabric with the print unit and the actual print data is fed to the print buffer sequentially to print the corresponding section of the fabric.   
     
     
         20 . The apparatus of  claim 19  wherein the plurality of threadings are a plurality of stitches in the fabric. 
     
     
         21 . The apparatus of  claim 19  wherein the plurality of threadings are a plurality of woven bindings in the fabric.